AKIRA CT-14GT9 Diagram

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CHASSIS: CN-ER

MODEL:

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CT-14GT9A

CT-14GT9CP

CT-14GT9N
CT-14GT9R

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

3

CONTENTS

Specifications ..........................................……………………………... 04-04

X-Ray Radiation Precaution …......………………….…………………. 05-05

Safety Precaution .............................................................................. 05-05

Product Safety Notice ……………………………………....……………05-05

Alignment and Test Instructions ........................................................ 06-14

Electrical Parameters of Main IC and Components ........................…15-19

Troubleshoot Flowchart .................................................................... 20-24

Schematic Diagram …………......………………………………………. 25-28

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

4

SPECIFICATIONS

RECEIVING SYSTEM

Sound System : A = BG/DK/I/M, R, N = BG/DK/I, CP = BG

Colour System : A = PAL/SECAM/NTSC/NTSC P/B

R, N = PAL/SECAM/NTSC P/B
CP = PAL/NTSC P/B

Picture Tube : 14” = 37cm diagonal
Ext. Antenna : 75 Ohm Coaxial Cable
Ext. In/Out : Audio/Video-in/out
Audio Output : 2W + 2W (THD ≤ 7%)
Volts : A = AC100 ~ 260V 50/60Hz
R, N, CP = AC150 ~260V 50/60Hz
Power Consumption : 14” = 60W
Dimension : 14” = 450(W) x 410(D) x 378(H) mm
Net Weight : 14” (10 kg)

REMOTE CONTROL

Transmitting System : Infra-red
Power Supply : DC 3V (1.5Vx2)

Design and specifications are subject to change without prior notice

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

5

CAUTION
Before serving the chassis, read the “X-Ray Radiation Precaution”, “Safety Precaution” and
“Product Safety Notice” on this page.

X-RAY RADIATION PRECAUTION

1. Excessive high voltage can produce potentially hazardous X-Ray Radiation. To avoid such hazards,
the high voltage must not be above the specified limit. The normal value of the high voltage of this
receiver is 24KV at zero beam current (minimum brightness) under 220V AC power source. The
high voltage must not, under any circumstances, exceed 30KV.

2. Each time a receiver requires servicing, the high voltage should be checked following the High
Voltage Check procedure in this manual. It is recommended the reading of the high voltage should
be recorded as a part of the service record. It is important to use an accurate and reliable high
voltage meter.

3. The primary source of X-Ray Radiation in this TV receiver is the picture tube. For continued X­Ray Radiation protection, the replacement tube must be exactly the same type tube as specified in
the part list.

4. Some parts in this receiver have special safety – related characteristics for X-Ray Radiation
protection. For continued safety, parts replacement should be undertaken only after referring to the
Product Safety Notice.

SAFETY PRECAUTION

Warning: Service should not be attempted by anyone unfamiliar with necessary precaution on this
receiver. The following are the necessary precautions observed before servicing this chassis.

1. Since the power supply circuit of this receiver is directly connected to the AC power line, an
isolation transformer should be used during any dynamic service to avoid possible shock hazard.

2. Always discharge the picture tube anode to the CRT conductive coating before handling the picture
tube. The picture tube is highly evacuated and if broken, glass fragment will be violently expelled.
Use shatter proof goggles and keep picture tube away from the unprotected body while handling.

3. When replacing a chassis in the cabinet, always be certain that all the protective devices are put
back in place, such as: non-metallic control knobs, insulating covers, shields, isolation resistor­capacitor network etc.

4. When replacing parts or circuit boards, disconnect the power cord.

5. When replacing a high voltage resistor (Metal oxide film resistor) on circuit board, keep the resistor
10mm (1/2in.)away from circuit board.

6. Connection wires must be kept away from components with high voltage or high temperature.

7. If any fuse in this TV receiver is blow, replace it with the FUSE specified in the chassis part list.

8. The receiver is designed to operate with 220V(50/60Hz) AC mains.

PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special safety –related characteristics. These
characteristics are often passed unnoticed by a visual inspection and the X-Ray Radiation protection
afforded by them cannot necessarily be obtained by using replacement components rated for high
wattage, etc. Replaced parts which have these special safety characteristics are identified in this manual
and its supplements, electrical components having such features are shaded on the schematic diagram and
the part list.

Before replacing any of these components, read the part list in this manual carefully. The use of substitute
replacement parts, which do not have the same safety characteristics, as specified in the part list may
create shock, fire, and X-Ray Radiation or other hazards.

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

6

ALIGNMENT AND TEST INSTRUCTION

MAIN CHASSIS ALIGNMENT INSTRUCTION

Equipment requirement:-

• Colour Television signal generator or Central TV signal generator

• IF alignment – Philips Gen. 5418 or 5518

• Scope 20 MHz – 2 channels types

• Digital multi-meter with LED display 4 digits

• Factory remote transmitting jig / Factory mode remote control unit

AV Input/Output Inspection

• Inspection Equipment

a. Standard video signal source (PAL)
b. Standard video signal source
c. (NTSC) S- VIDEO signal source
d. Audio signal source
e. Remote controller
f. Jig
g. Oscilloscope (Dual channel)

• AV Input Inspection

a. Set the TV to the AV mode. Send 1 Vpp (Loading: 75 ohm) PAL, NTSC and

SECAM AV signals into the AV IN terminals on the TV respectively. Check
and make sure that the picture, sound and color in every system are normal.

b. If the TV has front-set or side-set AV IN terminals, check the AV IN terminals

for normality.

c. If the TV has several sets of AV IN terminals, check every AV IN channel.
d. If the TV has S-VIDEO IN terminals, check the S-VIDEO IN channel.
e. If the TV can output AV stereo, inspect the AUDIO IN L/R channels

respectively.

Note: It's not necessary to check SECAM signal input if the TV can't receive SECAM signals.

• AV Output Inspection

a. Power on the TV to receive Z16 white full-field signal in the TV mode.
b. Check audio output with the oscilloscope and make sure that 1KHZ (1±0.2Vpp)

sine wave is available.

c. Check video output with the oscilloscope and ensure that l±0.2Vpp (Loading: 75

ohm) is available.

d. Send AV signals into the TV's AV IN terminals following the instructions stated

in 1.2 The TV should output different A V signals respectively.

Note: With S-VIDEO signal input, it's not necessary to check A V output.

Degaussing Coil inspection

• Inspection Requirement

a. Degaussing coil inspector

• Inspection Method

a. Dismount the automatic degaussing coil plug from the socket. After it cools,

remount the coil plug into the socket. Check internal degaussing effect and
ensure proper function. You may also use a magnetic sensor specially for
degaussing inspection

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

7

To Inspect Functions of Buttons and Remote Controller

• Inspection Equipment

a. Remote controller
b. Inspected Buttons on the TV
c. TV/A V
d. POSITION UP/DOWN
e. VOLUME UP/DOWN
f. MENU

• Inspected Buttons on the remote Controller

a. POWER ON/STANDBY
b. POSITION UP/DOWN
c. TV/A V
d. VOLUME UP/DOWN
e. OSD
f. MENU
g. MENU SELECT( ↑ / ↓ )
h. MENU ADJUSTMENT ( → / ← )
i. PICTURE MODE SELECT
j. PRESET
k. DIRECT SELECT ( 0 ∼ 9 and − / − −)
l. MUTE
m. OFF TIMER
n. GAME
o. BROWSE
p. OK

• To Inspect Functions of Buttons and Remote Controller

a. Power on the TV so that normal operation begin.
b. Check every button on the TV in turn and ensure that all buttons work normally

and feel smooth.

c. Check every button on the remote controller in turn and ensure that all buttons

work normally.

Inspection for Automatic Gain Control (AGC)

• Inspection Equipment

a. Remote transmitting jig

• Inspection Method

a. Check and make sure that both picture and sound are normal when the TV

receives 90dB signal, and signal to-noise ratio is O.K. with 90dB signal
reception. If not, press the AGC button to adjust AGC data until the above
requirements are fulfilled.

b. Check signals from other channels and ensure that the picture and sound are

normal.

Inspection for Sound Intermediate-frequency (SIF)

• Inspection Equipment and Signals

a. 70db standard multi-sound-system color TV signals
b. Remote transmitting jig
c. Audio voltmeter
d. Oscilloscope

• Inspection Method

a. Receive standard color TV signals in different sound systems (M, B/G, I, D/K)

respectively. Signal source is set to be modulation signal of 50KHz ±1KHz.

b. Press the SOUND SYS button on the remote transmitting jig to select proper

sound system respectively. Check AUDIO OUT terminals with the oscilloscope
and make sure that 1KHZ (1±0.2Vpp) sine wave is available and no noise and

buzz are generated from the speakers.

c. Measure the distortion-free voltage of the speakers to be no less than 4Vrms with

the audio voltmeter.

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

8

Aging

• Aging Setting

• Equipment to Be Required

• Remote controller

• Setting Method

• Set the volume to 0, and brightness, contrast and chroma to maximum.

• Set the TV in the M mode.

• Aging Voltage and Aging Time

• Increase the rated operating voltage by 10%, to 242V

• Aging time is not less than 2 hours.

Fine Tuning and Inspection After Aging

• Equipment and Signal to Be Required

• Voltmeter

• High-frequency effective voltmeter

• Anode high-voltage tester

• Adjustment and Confirmation of +B Voltage, Heater Voltage and Anode Voltage

• Power on the TV to receive grille pattern signal.

• Check the resistor and coil for being burned. (If the fuse is burned-out, do not power on the

TV again until the cause is found out.)

• Measure voltage of TP-I30 with the digital voltmeter and set voltage of the potentiometer
RP551 to 130 ± 1V

• Measure the heater voltage with the high-frequency effective voltmeter and anode voltage
with the anode high-voltage tester. The readings are shown as below.

Table

Test Point Type of voltage Voltage Value ( V )

Heater pin of socket Heater voltage
CRT anode (Small neck) High voltage
CRT anode (Large neck) High voltage

CRT anode (True flat) High voltage

CRT anode (14”) High voltage

Inspection for Purity and Convergence

• Purity Inspection

• Receive white full-field pattern signal (or red full-field video signal).

• Degauss the CRT.

• Check purity with monochromatic signals in magnetic-free equipment and ensure to come

up to the following standard.

• Convergence Inspection

• Receive grille pattern signal.

• Decrease the brightness and contrast properly to check convergence.

• Check if the convergence meets the following specifications.

• Convergence difference dependent on time in Section A should be less than O.5mm

• With supply voltage of 160~260V AC, convergence difference in Section A should be less

than 0.5mm

If not, readjust it again. Observe with a magnifying glass.

Section A: Purity offset is not allowed.

Note: Section A is a circle with effective screen height as its diameter.

Section B: 1/4 purity offset is allowed.

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0

6.3 ± 0.3V
25 ± 1.5kV
26 ± 1.5kV

26.5 ± 1.5kV

21.5 ± 1.5kV

9

Rough Adjustment of White Balance (Dark Balance Adjustment) and Focus Adjustment
Adjustment Equipment

a. Remote transmitting jig
b. Adjustment Method
c. In the TV mode, set the brightness to 32 and contrast, chroma, sub brightness

and sub contrast to 0. Set BLUE BACK off. Disconnect the signal cable.

d. Press the V KILL button on the remote transmitting jig so that the screen is

displayed as a horizontal bright line.

e. Adjust the screen potentiometer so that only a horizontal line appears on the

screen. Take the primary color accounting for a large proportion of the three
primary colors RGB as reference (for example, if the bright line is more green,
take G gun as reference.) Adjust dark balance of the other two primary colors
with the remote transmitting jig, but not adjust the reference gun. Roughly set
the bright line to white.

f. The horizontal line should not be too bright or too dark. If the line is too bright

or too dark, repeat step c. Then FIX the screen potentiometer.

g. Press the V KILL button on the remote transmitting jig so that raster appears on

the whole screen. Set the sub brightness and sub contrast to 63, and picture mode
to STANDARD.

h. Receive CH-5 circle pattern signals. Adjust FCB on the FBT until good raster

focus and high-definition picture are obtained.

Model No: CT-14GT9A_14GT9CP_14GT9N_14GT9R
Version 1.0